Answer:
x = 3 and x = 
Step-by-step explanation:
(a)
2(5x - 3) = 24 ( divide both sides by 2 )
5x - 3 = 12 ( add 3 to both sides )
5x = 15 ( divide both sides by 5 )
x = 3
(b)
5(2x + 1) = 50 ( divide both sides by 5 )
2x + 1 = 10 ( subtract 1 from both sides )
2x = 9 ( divide both sides by 2 )
x =
$90.05•1055=95,002.75
so the answer would be B. 95,000
First: work out the difference (increase) between the two numbers you are comparing. Then: divide the increase by the original number and multiply the answer by 100. % increase = Increase ÷ Original Number × 100. If your answer is a negative number, then this is a percentage decrease. ( copy and paste from skillsyouneed.com )
For this problem I would change:
2x + 3y = 25 into
-2x - 3y = -25
Then, I would add up both equations by lining them up top of another.
5x + 3y = 31
+ -2x - 3y = -25
3x = 6
x = 2
Now that you have x, solve for y.
5x + 3y = 31
5(2) + 3y = 31
10 + 3y = 31
3y = 21
y = 7
So, x is 2 and y is 7.
Check to see if the values are correct by plugging them into the other equation.
2x + 3y = 25
2(2) + 3(7) = 25
4 + 21 = 25
25 = 25
Since the values are correct, the solution to this problem is A (2, 7).
D
using the double - angle identity
cos (2A) = cos² A - sin² A = 2cos² A - 1 = 1 - 2sin² A
the right side = 1 - 2sin² (112.5° ) with A = 22.5°
hence 2A = 2 × 22.5° = 45°
thus cos 45° = 1 - 2sin² ( 22.5°)
